A 32-year-old woman, 6 hours post-cesarean section, develops sudden-onset severe abdominal pain, vaginal bleeding, and hemodynamic instability (BP 85/50 mmHg, HR 130/min). On examination, the abdomen is rigid and distended. The surgical team suspects uterine rupture. Which investigation will most rapidly confirm the diagnosis?

Explanation

## Clinical Presentation of Uterine Rupture This patient exhibits the **classic triad of uterine rupture**: 1. Sudden severe abdominal pain (often described as "tearing") 2. Vaginal bleeding and signs of PPH 3. Hemodynamic instability (shock) Uterine rupture is a **surgical emergency** requiring immediate diagnosis and intervention. ## Why Transabdominal Ultrasound is the Investigation of Choice **Key Point:** Transabdominal ultrasound is the **fastest, most accessible, and most specific** bedside investigation for uterine rupture because it: - Directly visualizes the uterine wall discontinuity (loss of normal contour) - Detects free fluid (blood) in the peritoneal cavity - Can be performed **at the bedside in <5 minutes** without patient transport - Requires no contrast or radiation - Allows simultaneous resuscitation and diagnosis - Has **sensitivity 90–100%** for detecting rupture with free peritoneal fluid **High-Yield:** In a **hemodynamically unstable patient with suspected uterine rupture**, the investigation must be: - **Rapid** (bedside, <5 min) - **Non-invasive** (no need to move the patient) - **Diagnostic** (confirms rupture and guides surgery) Ultrasound meets all three criteria. ## Comparison of Investigations | Investigation | Time to Diagnosis | Bedside? | Sensitivity for Rupture | Utility in Shock | |---|---|---|---|---| | **Transabdominal Ultrasound** | <5 min | Yes | 90–100% | Excellent | | Diagnostic Laparoscopy | 15–30 min | No | 100% | Delays definitive surgery | | Contrast-enhanced CT | 30–60 min | No | 95% | Contraindicated in unstable patients | | Diagnostic Peritoneal Lavage | 10–15 min | Yes | 85–90% | Outdated; rarely used | **Clinical Pearl:** In **hemodynamically unstable patients**, imaging must be **rapid and portable**. CT requires transport to the radiology suite and is contraindicated in shock. Diagnostic laparoscopy requires anesthesia and delays definitive laparotomy. **Mnemonic for uterine rupture diagnosis:** **RUSH** — Rapid Ultrasound in Shock. Bedside ultrasound is the standard for hemodynamically unstable patients with suspected intra-abdominal pathology.